It definitely shouldn't be too difficult to change the switches to ones of standard type... it is just the sheer number of switches across the network that add up into a lot of work. Each fix requires taking the switch offline while the concrete is cut up, the switch is installed on the currently unswitched rail, a cross beam is installed so the switches always point the same direction, and the concrete is filled back in. I don't understand why the TTC hasn't put a plan in place to make switches the industry standard type since it obviously limits their off-the-shelf options. If they had been updating the switches over the last ten years as they rebuilt the track almost all the switches would be dual-switch.
